This Multi-Clamp (formerly known as Safari Clamp) is precision machined from solid blocks of 6061-T6 aluminum. The hardware is stainless steel. The Multi-Clamp securely mounts to any round stock up to 3.5 inches (89mm). Or add the optional Flat Surface Adapters to mount to any flat surface up to 2.4 inches (63mm) in thickness. There are five threaded holes in the Multi-Clamp: four 3/8"-16 threaded holes, and one 1/4"-20 threaded hole. Use these built-in sockets to mount your attachments.
This is my first product from RRS. The built quality is exceptional. Functionally, this is definitely one of the best purchases I had made in recent years. I had this with me almost every travel trip and I had used this extensively in certain places like Hong Kong. The footprint requires for this clamp is so small, and the clamping strength can be so strong and stable on correct surfaces. I used this on hollow square railing and cylinder railing without any problem! Sensational!